Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753567AbdDNDv6 (ORCPT ); Thu, 13 Apr 2017 23:51:58 -0400 Received: from smtp.nue.novell.com ([195.135.221.5]:51965 "EHLO smtp.nue.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753352AbdDNDvz (ORCPT ); Thu, 13 Apr 2017 23:51:55 -0400 Date: Fri, 14 Apr 2017 11:51:19 +0800 From: Gary Lin To: hpa@zytor.com Cc: Thomas Gleixner , Ingo Molnar , x86@kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, Masahiro Yamada , Michal Marek , Matt Fleming , Ard Biesheuvel , Joey Lee , Vojtech Pavlik Subject: Re: [RFC PATCH] x86: Config options to assign versions in the PE-COFF header Message-ID: <20170414035119.v2kjxcsuauj3bdj2@GaryWorkstation> References: <20170411102041.19771-1-glin@suse.com> <8E544119-66B8-4482-BBE9-68B6C7A3AAE9@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8E544119-66B8-4482-BBE9-68B6C7A3AAE9@zytor.com> User-Agent: Mutt/1.6.2 (2016-07-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1975 Lines: 47 On Thu, Apr 13, 2017 at 03:21:20PM -0700, hpa@zytor.com wrote: > On April 11, 2017 3:20:41 AM PDT, Gary Lin wrote: > >This commit adds the new config options to allow the user to modify the > >following fields in the PE-COFF header. > > > >UINT16 MajorOperatingSystemVersion > >UINT16 MinorOperatingSystemVersion > >UINT16 MajorImageVersion > >UINT16 MinorImageVersion > > > >Those fields are mainly for the executables or libraries in Windows NT > >or higher to specify the minimum supported Windows version and the > >version of the image itself. > > > >Given the fact that those fields are ignored in UEFI, we can safely > >reuse > >those fields for other purposes, e.g. Security Version(*). > > > >(*) https://github.com/lcp/shim/wiki/Security-Version > > > >Cc: Thomas Gleixner > >Cc: Ingo Molnar > >Cc: "H. Peter Anvin" > >Cc: Masahiro Yamada > >Cc: Michal Marek > >Cc: Matt Fleming > >Cc: Ard Biesheuvel > >Cc: Joey Lee > >Cc: Vojtech Pavlik > >Signed-off-by: Gary Lin > >Tested-by: Joey Lee > >--- [snip] > > Reusing PECOFF fields seems doubleplusunsafe: we don't own those fields, the UEFI forum does. It would make a lot more sense to add these fields to the bzImage header directly or indirectly (via a pointer), the latter would be more economical since the bzImage header size is bounded. > > We could even define it as a pointer to a "security information header" with its own size field, so it can be grown in the future as needed. Reusing PE-COFF simplifies the implementation since shim can parse the header directly. I can raise the issue to the UEFI forum to clarify the usage of those fields. Meanwhile, I'll also look into the bzImage header in case the PE-COFF header is really a NO-GO. Thanks, Gary Lin